House filter systems split into two families: point-of-entry units that treat every drop entering the home, and point-of-use units that treat one tap. Within the whole-house family, the real choice is between cartridge housings and backwashing tank systems, and the media inside matters more than the shell. Pick the system by naming the problem first, not by shopping the category.
Point-of-entry versus point-of-use
A point-of-entry system sits where the supply line enters the house, so showers, laundry, ice makers and every faucet get treated water. It is the right scope for problems you experience everywhere: sediment, chlorine smell in the shower, iron staining. A point-of-use system, such as an under-sink unit, treats only drinking and cooking water and is the right scope for concerns that only matter in the glass. Many homes sensibly run both: a whole-house filter for the broad problem and a kitchen unit for the finish.
Cartridge housings versus backwashing tanks
Cartridge systems hold replaceable elements in one or more housings: simple, compact and cheap to buy, but every service is a manual cartridge swap and heavy loads exhaust them quickly. Backwashing systems hold a tank of loose media with an automatic control valve that periodically reverses flow, flushes what the media captured to the drain, and resets the bed. They cost more up front, need a drain and an outlet, and reward you with years of low-touch service. High sediment or iron loads generally justify the tank; light polishing duty suits cartridges.
The media decides what gets removed
Identical-looking tanks do completely different jobs depending on the media inside. Sediment media strains particles. Catalytic and activated carbon adsorb chlorine, taste and odor compounds. Air-injection oxidizing media precipitate iron and sulfur so they can be backwashed away. Neutralizing media raise acidic pH. None of them soften water: hardness is dissolved calcium and magnesium and needs ion exchange, which is a softener's job, not a filter's. Vendors such as SpringWell and US Water Systems publish the media and duty of each unit, which is the specification worth comparing.
Choosing by symptom
Work from the complaint backwards. Chlorine taste and smell on city water points to a whole-house carbon system. Orange or brown staining points to iron treatment. Cloudy water or gritty aerators point to sediment stages. Spotted glassware and scaled kettles point to a softener rather than a filter at all. Mixed symptoms on a private well usually mean a short train of stages, and a lab test settles the specification before you spend. Our whole house water filter guide goes deeper on sizing and flow ratings once you know which family you need.
Questions people ask about house filter systems
Does a house filter system remove hardness?
No. Hardness is dissolved calcium and magnesium, which passes through filtration media. Removing it takes a water softener using ion exchange, or scale-control conditioning if you only want scale reduction.
Do whole-house systems reduce water pressure?
Any filter adds some restriction, which is why systems carry flow ratings. Size the unit to your home's peak demand and service it on schedule, and the pressure effect stays unnoticeable.
Cartridge or backwashing: which lasts longer?
Backwashing tank systems typically run for years on the same media bed because they clean themselves to the drain. Cartridges are consumables by design and suit lighter duty or smaller budgets.
Where does a house filter system get installed?
On the main line where water enters the home, after the pressure tank on a well, ideally with a bypass loop so the house keeps water during service. Backwashing units also need a drain and an outlet.